title: Freeze-dried targeted mannosylated selenium-loaded nanoliposomes: development and evaluation.
abstract: The aim of this investigation was to develop and evaluate freeze-dried mannosylated liposomes for the targeted delivery of selenium. Dipalmitoylphosphatidylcholine, distearoylphosphatidylglycerol, and cholesterol were dissolved in a chloroform and methanol mixture and allowed to form a thin film within a rotatory evaporator. This thin film was hydrated with a sodium selenite (5.8 μM) solution to form multilamellar vesicles and homogenized under high pressure to yield unilamellar nanoliposomes. Se-loaded nanoliposomes were mannosylated by 0.1% w/v mannosamine (Man-Lip-Se) prior to being lyophilized. Mannosamine concentration was optimized with cellular uptake studies in M receptor expressing cells. Non-lyophilized and lyophilized Man-Lip-Se were characterized for size, zeta potential, and entrapment efficiency. The influence of liposomal composition on the characteristics of Man-Lip-Se were evaluated using acidic and basic medium for 24 h. Thermal analysis and powder X-ray diffraction were used to determine the interaction of components within the Man-Lip-Se. The size, zeta potential and entrapment efficiency of the optimum Man-Lip-Se were observed to be 158 ± 28.9 nm, 33.21 ± 0.89 mV, and 77.27 ± 2.34%, respectively. An in vitro Se release of 70-75% up to 24 h in PBS pH 6.8 and <8% Se release in acidic media (0.1 N HCl) in 1 h was observed. The Man-Lip-Se were found to withstand gastric-like environments and showed sustained release. Stable freeze-dried Man-Lip-Se were successfully formulated with a size of <200 nm, ≈ 75% entrapment, and achieved controlled release of Se with stability under acidic media, which may be of importance in the targeted delivery of Se to the immune system.
authors.affiliation: Department of Pharmaceutical Science, College of Pharmacy, University of Hawai'i at Hilo, 34 Rainbow Drive, Hilo, Hawaii 96720, USA.
authors.forename: Susanne R
authors.initials: SR
authors.lastname: Youngren
authors.forename: Rohit
authors.initials: R
authors.lastname: Mulik
authors.forename: Byoung
authors.initials: B
authors.lastname: Jun
authors.forename: Peter R
authors.initials: PR
authors.lastname: Hoffmann
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Morris
authors.forename: Mahavir B
authors.initials: MB
authors.lastname: Chougule
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005612:Freeze Drying; D008081:Liposomes; D008358:Mannose / Q000737:chemistry*; D051379:Mice; D049329:Nanostructures; D033362:Powder Diffraction; D012643:Selenium / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D008081:Liposomes; D012643:Selenium; D008358:Mannose